Anterior Sphincter-sparing Suturing of the Vesicourethral Anastomosis During Robotic-assisted Laparoscopic Radical Prostatectomy

Take Home Message Sparing the bladder neck and the intraprostatic urethra, together with the preservation of the periprostatic structures and refraining from stitching the anterior urethra with the adjacent anterior part of the urinary sphincter, leads to favourable urinary continence after robotic-assisted laparoscopic radical prostatectomy.


Introduction
Robotic-assisted radical prostatectomy (RARP) is a treatment option for men with localised prostate cancer. Treatment of prostate cancer is challenging due to competing oncological and functional goals [1][2][3]. As these outcomes are influenced by the surgical technique, several modifications to RARP that aim to preserve and/or reconstruct the delicate periprostatic structures have been introduced [4]. We illustrate a novel end-to-end anastomosis technique of the vesicourethral anastomosis during which the anterior bladder neck is stitched to the venous plexus instead of the anterior urethra. This approach avoids direct injury or indirect tension to the anterior muscular part, which is the most important aspect of the sphincter.

Informed consent
The study was approved by the Bioethics Committee (Swiss BASEC ID 2021-00181), and prior to surgery all patients signed an informed consent form to take part in this study. Patients were counselled about their diagnosis, prognosis, and different options for treatment specific to their disease, which may have included active surveillance, external beam radiotherapy, brachytherapy, and RARP. The expected benefits, risks, and likelihood of success for each option were discussed to ensure that the patient had sufficient understanding of the procedure and the potential risks specific to that individual. Surgical complications were dis-

Surgical procedure: closure and dressings
No drains are used [9]. The prostate is removed through the widened

Postoperative care
The patient can move, eat, and drink immediately after surgery. Our technique, which omits stitching of the anterior urethra, may lead to haematuria in some patients; this may require irrigation using a bladder syringe in selected cases. Thromboprophylaxis is prescribed once daily until discharge. Tadalafil (20 mg, twice weekly) is offered to all patients for penile rehabilitation during the first 12 wk after surgery.

Clinical follow-up
The patient is seen by the operating surgeon 10 d after surgery to remove staples and check wound conditions, and again 12 wk after surgery to assess functional results. Additional follow-up consultation is performed by the referring general practitioner or urologist. Prostatespecific antigen (PSA) measurements are recommended every 3 mo for 2 yr after surgery and every 6 mo for an additional 3 yr after surgery, after which yearly measurements are recommended. A biochemical recurrence has been defined as postoperative PSA >0.2 ng/ml.  supplemented by making individual phone calls. Urinary continence was defined as no pad use, whereas incontinence was defined as any amount of pad use, even the use of a safety pad [11]. All data were retrospectively analysed and reviewed. Statistical analyses were performed using R version 4.1.3 (R Foundation for Statistical Computing, Vienna, Austria).

Results
After the exclusion of 192 patients with a follow-up of <1 yr, 448 men treated between 2017 and 2021 with an RARP with the sphincter-sparing suture technique of the vesicourethral anastomosis were studied ( Table 1) One year after prostatectomy, 406/448 (91%) patients were continent, requiring no pad at all, while 42/448 (9%) required at least one pad per day. No interventions because of retention or stricture were reported.

Discussion
The most common side effect following RARP is urinary incontinence, which occurred in 74% of participants in the PROTECT study, a prospective randomised trial in the UK [12]. Similarly, results from the Scandinavian Prostatic Cancer Group Study Number 4 described urinary incontinence in 43% of patients (defined as any use of protection aid) 1 yr after surgery [13]. These results contrast with single-institution cohort studies of high-volume centres, which have reported urinary incontinence in as few as 11% of participants 3 yr after RARP [14]. These differences may be caused by patient selection, differences in outcome definitions, and/or differences in surgical technique.
In this study, we propose a further modification to the surgical technique by suturing the venous plexus instead of the anterior urethra, thereby sparing the urinary sphincter in this area. This technique may share some similarities with a periurethral suspension stitch [30], but it differs from other technical modifications, such as reconstruction of the posterior musculofascial [31][32][33] and/or anterior part of the vesicourethral anastomosis [34], Retzius-sparing approach [35], and the technique of suturing only the internal layer of the urethra without involving the outer rhabdosphincter [36]. Our technique not only spares the anterior internal layer, but also reduces tension on the sphincter by avoiding anterior stitches.
Our modification is based on the anatomical structure of the urethral sphincter, which has a circular horseshoe or omega shape, with more urinary sphincter fibres on the anterior aspect and fewer muscular fibres on the posterior aspect that end dorsally in the fibrous tendon [4,37]. This suggests that the anterior part of the urethra plays a more critical role in urinary continence mechanisms. Although our continence outcome showed that over 90% of patients required no pads at all after 1 yr of follow-up, the lack of a randomised control arm makes it challenging to quantify the influence of this surgical modification. The presented technique suggests early recovery of urinary continence as 123 (27)  8 32 (7)  9 30 (7)  only 15% of our patients demonstrated any measurable urine leakage in the 24 h after catheter removal, which seems to be a significant improvement compared with previous cohorts [38][39][40][41]. Our technique and description of outcomes have some limitations. Like any new surgical modification, our technique requires a certain learning curve. Additionally, the follow-up data, which were partly collected through phone interviews, may be affected by biases from either the respondent or the interviewer. Ideally, this new technical modification of the surgical technique should be evaluated within a prospective trial with a comparative arm that includes random allocation. Furthermore, in patients with apical prostate cancer, valid concerns have been raised regarding whether prostatic urethral preservation may compromise oncological outcomes [25].

Conclusions
We demonstrated a novel approach to suture the vesicourethral anastomosis during robotic-assisted laparoscopic radical prostatectomy that spares the anterior urethra and demonstrates favourable urinary continence results. Ideally a multi-institutional randomised trial with longer follow-up would be performed to properly define the exact benefits of this modification.
Author contributions: Christian Daniel Fankhauser had full access to all the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis.
Study concept and design: Fankhauser.
Analysis and interpretation of data: Antonelli.
Drafting of the manuscript: Antonelli, Fankhauser.
Critical revision of the manuscript for important intellectual content: Fankhauser, Mattei.
Administrative, technical, or material support: None.
Financial disclosures: Christian Daniel Fankhauser certifies that all conflicts of interest, including specific financial interests and relationships and affiliations relevant to the subject matter or materials discussed in the manuscript (eg, employment/affiliation, grants or funding, consultancies, honoraria, stock ownership or options, expert testimony, royalties, or patents filed, received, or pending), are the following: None.
Funding/Support and role of the sponsor: None.